Found in 3 comments on Hacker News
callahad · 2020-10-05 · Original thread
Which is a shame, because O'Reilly stopped selling ebooks more than three years ago: https://www.oreilly.com/content/the-mission-of-spreading-the...
lfowles · 2017-08-16 · Original thread
As noted in the post: "We’ve closed our online store, not our publishing operation!"

Original here: https://www.oreilly.com/ideas/the-mission-of-spreading-the-k...

adfm · 2017-07-03 · Original thread
Referenced below and applicable here, O'Reilly state they continue to support DRM-free formats (available from outlets that support them, like Google Play) and acknowledge the PDF issue in this post by Laura Baldwin.

https://www.oreilly.com/ideas/the-mission-of-spreading-the-k...